1. Field of the Invention
The present invention relates to a method for optically controlling optical devices such as optical recording media utilizing photochromic materials and the like, and to an optical control device utilizing such a method.
2. Description of Related Art
In recent years, extensive studies on photochromism have been made to investigate its applicability to optical information processing and recording. An attempt has been made to apply photochromic materials to a recording layer of an optical recording medium. Another attempt has been directed to provide a high density optical disk through a super resolution effect utilizing a photochromic masking layer.
In optical devices utilizing such a photochromic material, the photochromic material experiences a photon mode reaction upon irradiation with light. Typical light sources include semiconductor lasers and light-emitting diodes which are small in size and low in cost.
It is often required to irradiate the photochromic material with ultraviolet light if the photochromic material is to be colored to exhibit an increased absorption in a visible light region. However, currently available, short-wavelength light emitting devices provide an emitting light in a wavelength range from violet to blue. The coloring of the photochromic material by exposing them to ultraviolet light emitted directly from those semiconductor lasers or light emitting diodes has not been accomplished to this date.